Knockout for die casting machines



Nov. 10, 1942. J SAMABRQOK 2,301,819

KNOCKOU'I' FOR DIE CASTING MACHINES Filed May 17, 1940 2 Sheets-Sheet lZinncntor Nov. 10, 1942. 'F'. J. sAMBRooK 2;30 l,8l9

KNOCKOUT FOR DIE CASTING MACHINES Filed May 17, 1940 2 Sheets-Sheet 2Patented Nov. 10, 1942 z sorslc harem truce KNOCKOUT FGR DIE! CASTINGMACHINES Frank J. Sambrook, Dearhorn, Mich, assignor to Ternsted-tManufacturing Company, Detroit, Mich, a corporation of llfiichiganApplication May 17, 1940, Serial No. 335,814

1 Claim.

This invention relates to an improved and si plifiedform of ejector andknock-out mechanism for die casting machines. An object of g theinvention is to provide an ejector device which can be easily applied toexisting machines and which will not only separate the finished castingfrom the die but will free it completely from the machine at the end ofthe operating cycle without the usual manual removal and handling of thecasting which normally delays the succeeding casting operation and slowsdown production output.

A further object of the invention is to provide for the completedislodgment of the casting from the machine by the use of two or morepins moving together at a uniform rate initially to avoid bending of thecasting as its bond to the die is broken and thereafter at relativelydifferent rates and to different extent for breaking the smaller surfacebonds between the ejected casting and the ejector pins.

Additional objects and advantages will become apparent during the courseof the following specification having reference to the accompanyingdrawings wherein Figure 1 is a side elevation with parts in section of aportion of a die casting machine having the invention applied thereto;Figure 2 is an enlarged sectional view showing the dies and ejectormechanism in fully opened position and Figures 3 and 4 are detailedsectional views taken, respectively, on lines 3-3 and 4-4 of Figure 2.

The invention is especially adapted for use with the well known type ofdie casting machine having a vertical parting lin for the two part dieand an automatic operating cycle which includes, in timed sequence, theclosing of the dies, the injection of hot metal, the opening of the diesand the ejection of the casting from the die cavity. When the die halvesare parted the casting sticks to one of the mold halves and also to theends of the ejector pins exposed to the die cavity but is pushed out ofthe cavity by the automatic projection of the ejector pins. 01'-dinarily, the casting remains suspended within the space between theopen dies until its bond on the pins is broken, usually by means of asuitable tool in the hands of the workman who needs to leave thecontrols at the rear of the machine and step up and lean toward theparted dies to take hold and remove the casting and then return to thecontrols for again putting the machine into operation. The eliminationof this manual operation in accordance with the present invention willreduce hazard and work for the J operator as well as the time intervalbetween succeeding casting operations and the resultant greater outputper machine cuts down overhead costs and investments in additionalequipment and floor space.

The machine illustrated in the drawings consists essentially of a pairof relatively movable die blocks I and 2 with the die 2 fixedly mountedon the frame upright 3 and provided with a sprue opening through whichmolten metal is delivered to the die cavity from the nozzle 4. In theclosed position of the die a spreader 5 carried by the movable die Iextends into the sprue opening and distributes incoming metal throughoutthe multiple die cavity. The movable die carriage 6 is slidably mountedon a number of horizontal guide bars I fastened at opposite ends in theframe upright 3 and a similar upright 8 and is actuated through aplunger 9 from a suitable power source such as a piston motor, forexample.

The forwardly projecting die support IE! on the reciprocatory carriage 6has an enlarged hollow head, in the front shouldered portion of which ismounted, as by set screws I I, the die block I and in the space I2immediately behind the die block is slidably positioned the ejectorplate It. Extending rearwardly from the plate I3 through suitable guideopenings in th support It), is a rod I4 having a series of gear teeth onone side in mesh with a gear I5 located within a slot in the support I#3. The gear I5 is mounted on a stud or trunnion shaft I6 and is pinnedor otherwise secured to a rock lover I! which extends beyond the supportI!) and has its outer end coupled through a connecting rod I8 with thefixed upright 3. By reason of this operating connection the opening andclosing movements of the dies are transmitted to project and retract theejector plate It.

This ejector plate carries one or more ejector pins I9 directlyconnected thereto by threading an end of each pin into the plate, theprojecting portion thereof being slidable in an opening through themovable die I and of such length that its tip or outer surface will lieflush with the die cavity when the pin is retracted. Another ejector orknock-out pin 20 is slidably mounted in the die block I and is projectedforwardly by the ejector plate I3 through a motion moditying lever. Hereagain the relation of the parts is such that the tip surface of th pin20 lies flush with the die cavity in retracted position and the pin ismoved to this retracted position upon closing of the dies by itsengagement with the tip of a pusher pin 2|, aligned therewith andfastened in the stationary die 2.

The opening in the movable die 8, which slidably receives the pin 20, iscounterbored at its rear end and the resulting shoulder affords a stopto be engaged by a peripheral flange 22 on the pin to limit outwardmovement of the pin. At its inner end the pin 20 engages the free end ofa lever 23 located within a pocket in the rear face of the die i andfulcrumed on a pivot stud 24 carried by an insert or mounting bracket 25fixed to the die I. The rear edge of the lever 23 is formed to V-shapeand the point of convergence afiords an abutment pad indicated at 26 forengagement with the ejector plate l3 at a predetermined point in therange of forward movement of the ejector plate l3. At the fullyretracted position of the ejector plate the pad 26 is out of contact andthe ejector plate is in engagement with the free end of the lever asshown in Figure 1.

After the hot metal has been injected into the die cavity the dies areparted and the relative movement is transmitted to the ejector platethrough the link l8 causing it to move forward. In the initial portionof the range of travel the motion is transmitted from the plate [3directly to the ejector pins l9 and 20 so that the several pins areprojected outwardly in unison at the same rate to dislodge the castingfrom the die cavity as indicated by the broken lines in Figure 2. As thelever 23 is swung forward through this initial range, the abutment pad26 is brought into engagement with the ejector plate and thereafter theaction of the lever multiplies the motion transmitted to the pin 29 andthe pin 20 moves faster and farther than do the pins I9. In this finalportion of the range of travel of the ejector plate l3 the differentialmovement of the ejector pins cocks or tilts the casting with referenceto the tip surfaces of the pins and causes the bond of the casting tothe pins to be broken in the manner shown by the full lines in Figure 2.Thereupon the casting drops from between the dies and falls into asuitable receiver, such as a tray 2?, in the nature of an inclined chuteon which the casting can slide laterally from the machine into aquenching tank or the like.

As soon as the operating cycle is complete the machine is ready for thenext casting operation and there is eliminated any need for the operatorto leave his controls at the rear of the machine. From his controlstation the operator may look into the dies and observe the condition ofthe casting and the action of the ejection mechanism by the use of asuitable mirror (not shown) positioned opposite the parting line at theproper angle to give the reflected image.

I claim:

In a die casting machine having separable dies to one of which dies theformed castings have a tendency to cling, means operable afterdie-separation for positively dislodging the formed casting from the dieto which it tends to cling, comprising; a plurality of ejector pinsprojectable with respect to the matrix surface of said die, means foreffecting initial identical projection of said pins for incipientdislodgment of said casting, and pin-motion-modifying means actuated bysaid last-mentioned means after said incipient casting dislodgment forefiecting subsequent projection of one of saidequally-initially-projected pins at a materially greater rate thanothers thereof to positvely cook the casting and effect its facile finaldislodgment from said die.

FRANK J. SAMBROOK.

